Internal combustion engines (ICE) are often called upon to generate considerable levels of power for prolonged periods of time on a dependable basis. Many such ICE assemblies employ a mechanical supercharging device, such as a turbocharger (or turbine driven, forced induction supercharger), to compress the airflow before it enters the intake manifold of the engine in order to increase power and efficiency. Specifically, a turbocharger is a gas compressor that forces more air and, thus, more oxygen into the combustion chambers of the ICE than is otherwise achievable with ambient atmospheric pressure. The additional mass of oxygen-containing air that is forced into the ICE improves the engine's volumetric efficiency, allowing it to burn more fuel in a given cycle, and thereby produce more power.
Under extreme operating conditions, the “supercharging” process may elevate the temperatures of the intake air to an extent that causes the formation of undesired exhaust by-products, such as various nitrogen oxides (NOx), and reduces the density of the air charge. To combat this problem, ICE manufacturers have historically employed a device most commonly known as an intercooler, but more appropriately identified as a charge-air-cooler (CAC) or aftercooler, to extract heat from the air exiting the supercharging device. A CAC is a heat exchange device used to cool the air charge and, thus, further improve volumetric efficiency of the ICE by increasing intake air charge density through isochoric cooling. A decrease in air intake temperature provides a denser intake charge to the engine and allows more air and fuel to be combusted per engine cycle, increasing the output of the engine.
The heat exchange process can cause moisture (water) to condense and, thus, form inside of the CAC system, especially when conducted in conditions where the ambient air flowing through the supercharging device and CAC is substantially humid (e.g., greater than 50% relative humidity). The condensation tends to accumulate downstream from the CAC, within the conduit through which the intake manifold receives the supercharged airflow. The liquefied condensation can be drawn into the intake manifold, entering the various cylinder combustion chambers. Depending upon the configuration of the CAC and supercharging devices, as well as their individual and relative packaging, the condensation may begin to puddle and enter the combustion chambers in large amounts, potentially causing the ICE to misfire, leading to premature engine wear, and creating a false-positive error signal triggering a service engine indicator light. In addition, accumulated water condensate that is not properly evacuated from the CAC can freeze and crack the CAC when ambient temperatures reach below freezing.